This dissertation investigates whether social identity information modulates the interpretation of non-entailed clausal complement content (CC) in utterances of sentences such as (1): (1) Ken didn't hear that the minimum wage is too high. The focus of this dissertation is the listener 's inference that the speaker is committed to the truth of the CC, e.g., that the minimum wage is too low; to the extent that this inference holds, the CC is said to "project". I ask whether the social identities and beliefs of the interlocutors -- speaker and listener -- can influence projection inferences. With respect to the speaker, I ask whether the speaker's identity modulates these inferences. For example, are listeners more likely to infer that the speaker is committed t o a "conservative" CC such as the minimum wage is too high when the speaker is a Republican than when the speaker is a Democrat? With respect to the listener, I first ask whether listeners incorporate their own beliefs into their interpretations. Two type s of beliefs are investigated: listener beliefs about the speaker and listener beliefs about the CC. For listener beliefs about the speaker, the question is whether listeners ' beliefs about the speaker's beliefs, identity, and other social characteristics of the speaker modulate projection inferences. The second type of listener belief that I investigate is the listener's belief about whether the CC is true. For example, are listeners more likely to infer that the speaker is committed to a "liberal" CC if t hey themselves believe that the CC is true, compared to listeners who believe that it is false? I investigate these questions in a series of three experiments. Three speaker social identities that are stereotypically associated with political beliefs are explored: the speaker 's political affiliation (Republican vs. Democrat; Experiment 1), regional background (rural Southerner vs. nonrural non 2) and regional dialect (Southern accented vs. non-Southerner; Experiment Southern accented speakers; Experiment 3). This research contributes to our understanding of how social identity information shapes linguistic interpretation. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]